Thisstudywasdesignedtounderstandtheimpactofmethylbromide(MB)(CH3Br)anditsalternativesonbothfree-livingandroot-knotnematodesinthesoil.Arandomizedcompleteblockexperimentwithsixtreatmentsand4replicates(eachreplicateinaseparategreenhouse)wasestablishedinQingzhou,ShandongProvince,China.InadditiontoMBanduntreatedcontrol(CK)treatmentstherewerefouralternativesoilfumigationpracticesincludingMB+virtuallyimpermeablefilms(VIF),metamsodium(MS),MS+VIFandsoilsolarizationcombinedwithselectedbiologicalcontrolagents(SS+BCA).Twotomato(LycopersicumesculentumMill.)cultivars,cv.Maofen-802fromtheXianInstituteofVegetableScience,China,andcv.AF179BrillantefromtheIsraeliHazeraQualitySeeds,wereselectedastestcrops.TheresultsindicatedthatRhabditidaewasthemostdominantpopulationwithpercentageabundanceashighas85%ofthetotalnumberofidentifiedfree-livingnematodes,followedbythatofCephalobidae.Methylbromideanditsalternativesexceptforthenon-chemicalSS+BCAtreatmentcontrolledthetargetpest,root-knotnematodes.Also,theimpactofthethreechemicalalternativesonfree-livingnematodenumberandfunctionalgroupabundancewassimilartotheimpactassociatedwithatypicalmethylbromideapplication.Chemicalfumigationpractices,especiallythatwithMB,significantlyreducedthenumberofnematodesinthesoilandsimultaneouslysignificantlyreducedthenumberofnematodegeneratherebyreducingnematodepersity.Allthefoursoilchemicalfumigationactivitiesdecreasedsoilmicrobialbiomassandhadanobviousinitialimpactonmicroorganismbiomass.Furthermore,bothplant-parasiticandfungivorenematodeswerepositivelycorrelatedwithsoilmicrobialbiomass.
